Cationic and anionic lignin amines corrosion inhibitors

ABSTRACT

Lignin amines are disclosed which are characterized by high nitrogen content and are water soluble at both alkaline and acidic pH values. The lignin amines have utility as flocculants, filtration aids, precipitants, scale inhibitors, asphalt emulsifiers, fluid loss additives, oil well cement additives, corrosion inhibitors, retention aids, cationic dispersants, and tall oil pitch emulsifiers.

This is a division, of application Ser. No. 076,948, filed July 23,1987.

BACKGROUND OF THE INVENTION

This invention relates to protonated lignin-polyamines, quaternaryammonium salts of lignin polyamines and sodium-, potassium-, salts oflignin polyamines.

The objective of this invention is to provide new improved ligninamines, which are characterized by high nitrogen content and are watersoluble at both alkaline and acidic pH values. In addition, a widevariety of applications for these products is described.

The most widely applicable method to introduce a nitrogen functionalityinto lignin is by the Mannich Reaction, which involves condensation ofammonia, primary or secondary amine and a suitable aldehyde onto theunsubstituted position ortho to the phenolic hydroxyl group. Themanufacture of amines from kraft lignin by this method is disclosed inU.S. Pat. No. 2,863,780 by J. C. Ball and U.S. Pat. No. 2,709,696 by E.G. Wiest. Kraft lignin is obtained from the spent lignin of the kraftpulping process by acidification. This lignin is insoluble in water atpH values from 1 to 7 and soluble at pH values of 8 and above. Thepreparation of aminoalkylated lignin prepared from hydroxyphenylatedlignosulfonate is disclosed in U.S. Pat. No. 4,017,475 by C. H. Ludwig.Lignosulfonates are isolated from spent sulfite liquors, a by-product ofthe sulfite pulping process. Dihydro-oxazine derivatives of kraft ligninobtained by reaction of kraft lignin with methyl amine and formaldehydeare disclosed in Canadian Pat. No. 1,018,520 by A. B. McKague,quaternary ammonium salts based on aminomethylated lignins are disclosedin U.S. Pat. No. 3,407,188 by G. A. Cavagna, and Canadian Pat. No.1,018,519 by A. B. McKague. A variety of kraft and sulfite ligninscontaining quaternary ammonium-functionalities are disclosed in U.S.Pat. Nos. 3,470,148 and 3,600,308 by G. G. Allan and in U.S. Pat. Nos.3,857,830 and 3,935,101 by W. S. Briggs.

In the recent U.S. Pat. No. 4,455,257 by H. W. Hoftiezer, et al., the"cationic" reaction products of kraft lignin with aldehyde and polyamineare disclosed. These products and the above described Mannich-ligninamines are useful as flocculating agents for clay and other finelydivided materials. However, the reaction products of lignin,formaldehyde and polyamines, as described in U.S. Pat. No. 4,455,257, infact, are not soluble at acidic pH values and they are also not insolution when they are prepared at alkaline pH values.

DESCRIPTION OF THE PREFERRED EMBODIMENT

This invention describes a method whereby lignin-polyamine-aldehydecondensates are obtained which are soluble in water at both acidic andalkaline pH values.

Although the polyamines behave as bases, their basicity is not highenough to dissolve kraft lignin in water to yield 25-30% solutions byweight. By blending polyamines with kraft lignin in aqueous suspensionsas described in U.S. Pat. No. 4,455,257, heterogeneous mixes areobtained which do not become homogeneous upon heating. In contrast tothis procedure, homogeneous solutions are obtained when water-insolubleprecipitated kraft lignin is slurried in water and the pH value isincreased to at least 10 by addition of sodium hydroxide or potassiumhydroxide, and the proper amount of a polyamine is added. The Mannichreaction is carried out by addition of formaldehyde or other suitablealdehydes to these blends and heating to 50°-100° C. The lignins haveundergone the Mannich reaction when upon dilution to 10% solids andaddition of dilute hydrochloric acid, clear solutions at pH values of1.0-4.0 are obtained.

This disclosure describes lignin amines which have many applications,including flocculants, filtration aids, precipitants, scale inhibitors,asphalt emulsifiers, fluid loss additives, oil well cement additives,corrosion inhibitors, retention aids, cationic dispersants, and tall oilpitch emulsifiers.

It has been shown that various lignin sources can be used as startingmaterial for the Mannich reaction as described below (I-III): ##STR1##

Softwood and hardwood lignin derived from the kraft pulping process arethe preferred raw materials, with softwood lignin having the highermolecular weight and lower number of methoxy groups in the molecule. Atechnical description of kraft lignin can be found in Lignin,Occurrence, Formation, Structure and Reaction, K. V. Sarkanen and C. M.Ludwig, Eds., Wiley-Interscience: New York-London-Sidney-Toronto 1971,p. 639-691.

The number of active reaction sites for the methylolation (formaldehydecondensation) can be increased by reaction of kraft lignins with strongbases whereby demethylation of the methoxy-groups occurs: ##STR2##

This demethylation can be achieved also by heat treatment of the sodiumor potassium lignates in the presence of amines or polyamines used forthe subsequent Mannich reaction.

Another suitable lignin is that derived from the vanillin process, inwhich sulfite lignin is oxidized under pressure, resulting indegradation to vanillin and residual lower molecular weight lignin,containing a minimal number of sulfonic acid groups. Generally,lignosulfonic acids isolated from spent sulfite liquors can bedesulfonated by heat treatment with strong bases such as sodiumhydroxide or potassium hydroxide, as well as amines or polyamines.

Lignin amines containing a significant amount of sulfonic acid groupscan be obtained by using lignosulfonic acids as starting material. Theseproducts are either isolated from spent sulfite pulping liquors or canbe derived by high temperature sulfonation, oxidative sulfonation atambient temperature, or sulfomethylation (reaction with sodium sulfiteand formaldehyde) of kraft lignin, i.e., sulfonated kraft lignin.

Alkaline bark extracts or peat moss are also useful aromatic startingmaterials for the aminoalkylation.

Prior to the Mannich reaction the lignins can be modified to suitspecific applications. The molecular weight may be increased by reactingkraft lignin or any other suitable lignin, such as modified kraftlignins and lignosulfonates, with 0.1-1 mole of a crosslinking agent per1,000 grams of lignin. Crosslinking may occur by binding two ligninmolecules via unsubstituted ring positions (V). Aldehydes, such asformaldehydes or di-aldehydes such as glyoxal or glutaraldehyde aresuitable reagents for this reaction. Unsaturated aldehydes such asacrolein or crotonaldehyde may also be used. ##STR3##

Another option to induce crosslinking and molecular weight via thearomatic nuclei is by oxidation. One-electron transfer oxidants such aspotassium ferricyanide, are the preferred agents, but alkali metalpersulfates, hypochlorites or peroxides may also be used. In theseoxidations the alkali lignates are oxidized to the corresponding shortlived radicals (VI), which upon combination form aryl-aryl linkages(VII), or phenoxyl-aryl linkages (VIII), resulting in increasedmolecular weight. ##STR4##

Lignins with increased molecular weight also can be obtained by reactingthe corresponding alkali lignates with bi-functional or tri-functionalalkylating agents such as di-halo alkanes (IX), epichlorohydrin (X),polyethylene oxides or polypropylene oxides with terminal reactivegroups such as chloride, bromide, tosylate (XI), diepoxides (XII), orcyanurchloride (XIII). ##STR5##

Lignins also can be modified to suit certain applications withoutsignificantly changing the molecular weight by partial alkylation of thephenolic hydroxyl groups under alkaline conditions. Alkylating agentsuseful for this modification are alkylhalides, alkylsulfates oralkylphosphates (XIV), and epoxides such as ethylene oxide, propyleneoxide, butylene oxide (XV), styrene oxide (XVI), and cyclohexene oxide(XVII). ##STR6## Alkylating agents containing sulfonic acid groups suchas haloalkane sulfonic acids (XVIII), chlorohydroxy propane sulfonicacid (XIX) or propane sultone (XX) are also useful to modify lignin viaO-alkylation. ##STR7## Haloalkane carboxylic acid (XXI), acrylic acid(XXII), methacrylic acid (XXIII) or acrylonitrile (XXIV) may be used tointroduce carboxy-functionalities into the lignin molecule prior toaminoalkylation. ##STR8## Alkylating agents containing nitrogen aredialkyl aminoalkyl halides (XXV) or the quaternary trialkyl ammoniumsalts (XXVI) derived from epichlorohydrin and tertiary amines. ##STR9##

All the above described modifications of lignin or lignosulfonates canbe carried out in aqueous solution or, when necessary, in organicsolvents or mixtures of organic solvents and water.

Polyamines suitable to undergo the Mannich reaction with formaldehyde orother aldehydes as well as polyaldehydes are imidazoline formingpolyethylene amines and polyamines characterized by at least oneethylene diamine functional group with at least three hydrogens attachedto the two nitrogens (XXVII). Compounds of this group which are able togive both amidoamines and imidazolines are: ethylene diamine, diethylenetriamine, triethylene tetramine, tetraethylene pentamine, pentaethylenehexamine, and higher homologues; N-aminoethylpropane-diamine,N,N-diaminoethyl propane diamine and the N-aminoethyl orN,N-diaminoethyl substituted butane diamines, pentane diamines andhexane diamines, as well as N-hydroxy ethyl ethylene diamine. Thesecompounds have the general formulae: ##STR10##

Amines capable of forming amidoamines but not imidazolines are:1,3-diaminopropane; 1,4-diaminobutane; 1,5-diaminopentane;1,6-diaminohexane; piperazine (1,4-diazacyclohexane); N-aminoethylpiperazine; N-hydroxyethyl piperazine; N-aminopropyl-propane diamine;1,3-N-methyl N-aminopropylpropane diamine; 1,3-N,N-dimethylpropanediamine; 1,3-N,N-diethyl propane diamine; 1,3-N,N-dimethylethylenediamine; N,N-diethylethylene diamine; N-aminohexyl hexane diamine-1,6.

Diamines whereby the amino groups are separated by polyethylene oxidechains or polypropylene oxide chains are also very suited for theMannich reaction. ##STR11##

The above described amines can be further modified by reaction with anyof the alkylating agents or crosslinking agents (IX-XVI) described inconnection with lignin modification. Modified amines or amine mixtureswih increased molecular weight or amines which have additional reactivefunctionalities such as sulfonic acid, carboxyl, hydroxyl, nitrile, andquaternary-ammonium groups will be obtained. For the aminomethylation,however, it is necessary that at least one hydrogen on any of thenitrogens of the parent polyamine be available for the condensation withformaldehyde.

Suitable reactants for the Mannich reaction are: aldehydes such asformaldehyde (the preferred reagent), benzaldehyde, or other tertiaryaldehydes; dialdehydes such as glutaraldehyde and glyoxal; orunsaturated aldehydes such as acrolein or croton aldehyde.

Generally, the reaction is carried out by suspending the acid-insolubleprecipitated kraft lignin in water at a solids content of 15-30%, andadjusting the pH value to 10-12 by addition of potassium hydroxide orsodium hydroxide. At this point most of the lignin has undergonedissolution. In the subsequent step the proper amount of the desiredamine is added. The addition of the amine is accompanied by atemperature increase and increase in pH value. To the homogeneousmixture of potassium or sodium lignate and polyamine the required amountof aldehyde is added and heated for 2-20 hours at 50°-100° C. Thereaction can also be carried out by precondensing polyamine and aldehydeat ambient temperature and adding this precondensate to the alkalinesolution of lignin. The preferred reaction medium is water, or, ifrequired, mixtures of water and organic solvents. Organic solvents alsocan be used for this reaction.

To fit certain applications, the lignin-formaldehyde polyaminecondensates may be further modified by reaction with any of the abovementioned crosslinking agents, or alkylating agents (IX-XVI).

These reagents will react with both the nitrogens of the polyaminofunctionalities and the phenolic hydroxyl groups of the lignin. Thereaction product of kraft lignin with aminoethylpiperazine,formaldehyde, and chlorohydroxypropyl-trimethyl ammonium chloride willserve as an example of a highly cationic lignin: ##STR12##

In most cases the pH values of the lignin polyamine solutions are above10. For certain applications, such as flocculation of finely dispersedmatter, it has been found that the protonated lignin polyamines whichbear a highly positive charge perform in a fashion superior to theparent lignin amine in the form of the sodium or potassium salt. Thischarge reversal is achieved by diluting the alkaline lignin polyaminesolution to the proper concentration and adjusting the pH value to 1-4by addition of a suitable mineral or organic acid such as hydrochloricacid, hydrofluoric acid, sulfuric acid, acetic acid or formic acid. Inmany applications, solutions of the ingredients which perform thedesired functions are applied. However, in certain instances dryingredients are the preferred additives.

Since the lignin-formaldehyde-polyamine condensates behave asaminoplasts, polymerization occurs when solutions are spray dried ortray dried at elevated temperatures rendering the lignin insoluble. Thispolymerization reaction occurs at alkaline as well as acidic pH values.It has been found that the addition of low molecular weight substanceswhich are stable at these pH values and which will react withformaldehyde will suppress or terminate the polymerization, yieldingsoluble dry lignin-polyamines of the desired molecular weight. Below pH7, the preferred spray drying aid is urea, which at a concentration of1-5% based on the weight of the lignin polyamine insures that a watersoluble, dry lignin-polyammonium hydrochloride (acetate, formate, etc.)is obtained. Above pH 7, the preferred spray drying acid is phenol, ofwhich 1-5% concentration based on the weight of the lignin polyaminewill ensure that a water soluble dry lignin-polyamine-alkali-salt willbe obtained.

The practice of this invention may be seen in the following exampleswherein preparation of various types of lignin-polyamine-aldehydecondensates and their applications are described.

EXAMPLE 1

Kraft lignin reacted with ethylene amine E-100 according to Example 6 ofU.S. Pat. No. 4,455,257, which procedure is incorporated herein byreference, resulted in a water insoluble reaction product which was notsoluble at acidic pH values. However, when the reaction was carried outin the presence of sodium hydroxide, a clear solution of the reactionproducts resulted. The kraft lignin/E-100 prepared according to thisprocedure were soluble at pH values ranging from 1.5-3.0.

EXAMPLE 2

The improved procedure can be also shown by the performance of thepolyethylene-kraft lignin condensate as flocculant for secondarypapermill sludge. Addition of 0.5% of these products based on sludgesolids (1.93% solids concentration) and pH-value adjustment to 2.5resulted in filtration times of 35.7 sec. and 52.8 sec. for 100 mlsludge. The product prepared according to this invention with sodiumhydroxide present resulted in better floc-formation and thus fasterfiltration rates.

EXAMPLE 3

Into 400 ml of water is slurried 100 grams precipitated softwood kraftlignin, and the pH value is adjusted to 11.0 by adding 50% sodiumhydroxide dropwise. After the pH value remains constant, 25-125 gramsaminoethylpiperazine is added and stirred for 30 minutes. Theconcentration of the blend is adjusted to 25% by addition of the properamount of water. To the well-stirred mixture 16.2-81.1 grams 37%formaldehyde is added and heated at 95°-100° C. for 3-16 hours.

EXAMPLE 4

Into 400 ml of water is slurried 100 grams precipitated softwood kraftlignin and the pH value is adjusted to 11.0. After addition of 8.1 grams37% formaldehyde the reaction mixture is heated at 90° C. for 12-16hours. The mixture is then cooled to 70° C., and 25-125 gramsaminoethylpiperazine and 50-250 grams water are added. The mixture isstirred for 30 minutes, and 16.2-81.1 grams 37% formaldehyde is addedand after dilution to 20% solids is heated at 95°-100° C. for 3-16hours.

EXAMPLE 5

Into 400 ml water is slurried 100 grams precipitated softwood kraftlignin, and the pH value is adjusted to 11.5 by addition of 50% sodiumhydroxide. The temperature is increased to 70° C., and with vigorousstirring 4.5 grams epichlorohydrin is added dropwise. After two hoursthe epichlorohydrin has disappeared, and the pH value is readjusted to11.0. To this mixture 20-100 grams diethylenetriamine is added andstirred for 30 minutes followed by the addition of 16.2-81.1 grams 37%formaldehyde and dilution to 20% solids. The mixture is then heated95°-100° C. for 5-16 hours.

EXAMPLE 6

Into 1,000 ml water is slurried 200 grams precipitated softwood kraftlignin, and sodium hydroxide (20% based on weight) is added. Thereaction mixture is then transferred to a pressure reactor (Parrreactor) and heated to 180°-200° C. for 5-8 hours. After cooling, thereaction mixture is diluted to 15% solids; and the pH value is loweredto 2 by the addition of 10% sulfuric acid. The precipitated demethylatedlignin is filtered through a Buchner funnel and washed several timeswith water.

Into 400 ml water is slurried 100 grams of the precipitated-demethylatedsoftwood lignin, and the pH value is adjusted to 11.0 with 10% sodiumhydroxide. To this mixture 28.5-145 grams triethylenetetramine is addedslowly and stirred for 30 minutes. After the addition of 16.2-81.1 grams37% formaldehyde and dilution to 20% solution, it is heated at 95°-100°C. for 4-16 hours.

EXAMPLE 7

Into 400 ml water is slurried 100 grams precipitated kraft lignin, andthe pH value is adjusted to 11.0 by addition of 50% sodium hydroxide.With good stirring 32 grams 60% solution of DOWQUAT 188®(chlorohydroxypropyltrimethyl ammonium chloride) is added and heated to70° C. for 5 hours. At the end of this period the pH value is readjustedto 11.0 with sodium hydroxide, and 25-125 l grams aminoethylpiperazineis added and stirred for 30 minutes. After the addition of 16.2-81.1grams 37% formaldehyde and dilution to 20% solids, the reaction mixtureis heated at 95°-100° C. for 3-17 hours.

EXAMPLE 8

Into 400 ml water is slurried 100 grams precipitated softwood kraftlignin, and the pH value is adjusted to 11.0 with 50% sodium hydroxide.To this solution is added 200 ml 5% sodium hypochlorite solution and themixture heated to 90° C. for 1 hour. After cooling, 20-100 gramstriethylenetetramine and 16.2-81.1 grams 37% formaldehyde are added anddiluted with water to 20% solids followed by heating at 95°-100° C. for4-12 hours.

EXAMPLE 9

Into 400 ml water is slurried 100 grams precipitated softwood kraftlignin, and the pH value is adjusted to 11.0 with 50% sodium hydroxide.To this solution are added 25-125 grams aminoethylpiperazine and16.2-82.1 grams 37% formaldehyde. It is then heated at 95°-100° C. for4-6 hours. After cooling, 32-320 grams 60% DOWQUAT 188® solution isadded in small increments. During the addition, the pH value is kept at10.5-11.0 by adding increments of 50% sodium hydroxide. It is heated at60°-70° C. for 3-5 hours.

EXAMPLE 10

Into 400 ml water is slurried 100 grams precipitated hardwood kraftlignin and the pH value adjusted to 11.0 with 50% sodium hydroxide. Tothis solution is added 9 grams propylene oxide and the reaction mixturestirred overnight at 50° C. (in a pressure reactor). To this is added20-100 grams diethylene triamine and 16.2-81.1 grams formaldehyde, andafter dilution to 20% solids the reaction mixture is heated at 95°-100°C. for 4-12 hours.

EXAMPLE 11

Into 400 ml water is slurried 100 grams precipitated softwood kraftlignin and 31.5 grams sodium sulfite and 4.1 grams 37% formaldehydeadded. The solids content is adjusted to 25%, and the mixture istransferred into a pressure reactor (Parr reactor). It is then heated at125°-135° C. for 3 hours and cooled. To this solution are added 50 gramsaminoethylpiperazine and 34 grams 37% formaldehyde. After adjustments ofthe solids content to 25%, the solution is heated at 95°-100° C. for 6hours.

EXAMPLE 12

This example shows how the anionic form of the lignin polyamine istransformed into the cationic species, the active form to be used inflocculation, precipitation, and retention of finely divided matter.

The alkaline solution of a lignin polyamine prepared according toExample 1 through 9 is adjusted to 10% solids with water or a watermiscible solvent and the addition of dilute hydrochloric acid, sulfuricacid, phosphoric acid, acetic acid or formic acid; the pH value islowered to 1-3. With the exception of the quaternized lignin polyamines,the lignin amines precipitate out of solution at the neutral pH valuecoinciding with their isoelectric points. Therefore, to ensure fastdissolution, vigorous agitation is recommended.

EXAMPLE 13

To 103 grams diethylenetriamine diluted with 309 grams water, 45 gramsepichlorohydrin is added very slowly over a period of 1 hour and kept at50° C. for 4 hours. Into 400 ml water 100 grams precipitated softwoodkraft lignin is slurried, and the pH value adjusted is 11.0 with 50%sodium hydroxide. To the lignin solution 29.6 gramsdiethylenetriamine/epichlorohydrin reaction product (91.4 grams of theabove solution) and 16.2 grams 37% formaldehyde are added and heated at90° C. for 5 hours.

EXAMPLE 14

To 103 grams diethylenetriamine diluted with 309 grams water, 316 grams60% DOWQUAT 188® solution is added with stirring and heated at 70° C.for 3 hours. It is cooled, and 80 grams 50% sodium hydroxide is added.Into 400 grams water 100 grams precipitated softwood kraft lignin isslurried, and the pH value is adjusted to 11.0 with 50% sodiumhydroxide. To this solution 59 grams of the diethylenetriamine/DOWQUAT188® reaction product (161.6 grams of the above solution) and 16.2 grams37% formaldehyde are added and heated to 90° C. for 6 hours.

EXAMPLE 15

This example shows the utility of the lignin polyamines as dewateringaids for secondary papermill sludge. To 200 ml secondary papermillsludge various amounts of PERCOL 763®, a cationic polyacrylamide (AlliedColloids), and/or an acidified lignin amine solution is added withgentle stirring. The flocculated sludge is filtered on a Buchner funnelunder vacuum (25 psi), and the time required to collect 100 ml filtrateis measured.

Table I shows the improvement in filtration rate of the sludge, colorreduction of the filtrate, and the synergistic effect on both propertieswhen a high cost synthetic cationic polyacrylamide is added to thelignin polyamine. Several other lignin-formaldehyde-polyaminecondensates prepared with ethylenediamine, diethylenetriamine,triethylenetetramine or higher homologues are as effective.

                  TABLE I                                                         ______________________________________                                        FILTRATION OF SECONDARY PAPER MILL SLUDGE                                                             Fil-                                                                          tration                                                                       Time    Color of                                      Flocculant.sup.(a)      (sec.)  Filtrate                                      ______________________________________                                              No flocculant added   185     yellow                                    250 mg                                                                              Lignin amine as sodium salt.sup.(b)                                                                 192     yellow                                    50 mg Lignin amine as ammonium chloride.sup.(c)                                                           90      slightly                                                                      yellow                                    100 mg                                                                              Lignin amine as ammonium chloride                                                                   55      colorless                                 150 mg                                                                              Lignin amine as ammonium chloride                                                                   45      colorless                                 250 mg                                                                              Lignin amine as ammonium chloride                                                                   45      colorless                                 5 mg  PERCOL 763 ®      153     yellow                                    10 mg PERCOL 763 ®      130     yellow                                    15 mg PERCOL 763 ®      85      yellow                                    20 mg PERCOL 763 ®      20      yellow                                    25 mg Lignin amine as ammonium chloride.sup.(c)                                                           13      slightly                                  10 mg PERCOL 763 ®              yellow                                    50 mg Lignin amine as ammonium chloride.sup.(c)                                                           17      colorless                                 10 mg PERCOL 763 ®                                                        ______________________________________                                         .sup.(a) Amount of flocculant is added based on 100% activity.                .sup.(b) Prepared as described in Example 1.                                  .sup.(c) The preferred product is a condensation product of softwood kraf     lignin, aminoethylpiperazine/triethylenetetramine blend and formaldehyde      acidified with hydrochloric acid as described in Example 10.             

EXAMPLE 16

In this example, Tables II and III show the improved performance of thelignin polyamines as filtration aids for secondary papermill sludge whenthey are prepared according to Example 1 and post-reacted with DOWQUAT188® as described in Example 7.

                  TABLE II                                                        ______________________________________                                        FILTRATION OF SECONDARY SLUDGE CONDITIONED                                    WITH 9 GRAMS 0.5% FLOCCULANT SOLUTION                                         PER 200 ml SLUDGE                                                                            Filtration Time                                                               (sec.)                                                         Flocculant.sup.(a)                                                                             Sludge #1 Sludge #2                                          ______________________________________                                        No flocculant    214       240                                                Lignin polyamine.sup.(b)                                                                       106                                                          [LPA]--1N.sup.+(c)                                                                             93                                                           [LPA]--2N.sup.+(c)                                                                             94                                                           [LPA]--3N.sup.+(c)                                                                             89                                                           [LPA]--4N.sup.+(c)         85                                                 [LPA]--5N.sup.+(c)         90                                                 ______________________________________                                         .sup.(a) Adjusted to pH 2.5.                                                  .sup.(b) Kraft lignin reacted with 3 moles aminoethylpiperazine and 5         moles formaldehyde per 1,000 grams lignin, [LPA].                             .sup.(c) Reacted with number of moles DOWQUAT 188 ® per 1,000 grams       lignin polyamine [LPA].                                                  

                                      TABLE III                                   __________________________________________________________________________    FILTRATION OF SECONDARY SLUDGE CONDITIONED                                    WITH PERCOL 763/LIGNIN AMINE BLENDS                                           (0.5% Solution)                                                                               Amount                                                                        of     Filtration                                                             Flocculant.sup.(a)                                                                   Time                                                   Flocculant      (ml)   (sec.)                                                 __________________________________________________________________________    No flocculant   --     228                                                    Lignin polyamine [LPA]                                                                        5.0    70                                                     PERCOL 763 ®.sup.(b)                                                                      5.0    29                                                     [LPA]--4N.sup.+(c)                                                                            5.0                                                           PERCOL 763 ®.sup.(b)                                                                      5.0    16                                                     [LPA]--4N.sup.+(c)                                                                            5.0                                                           PERCOL 763 ®.sup.(b)                                                                      5.0    57                                                     PERCOL 763 ®.sup.(b)                                                                      9.0                                                           __________________________________________________________________________     .sup.(a) 0.5% lignin amine solution at pH 2.5; ml per 200 ml                  .sup.(b) Polyacrylamide (Allied Colloids)                                     .sup.(c) Lignin polyamine reacted with 4 moles DOWQUAT 188 ® per 1,00     grams [LPA                                                               

EXAMPLE 17

This example shows the utility of an acidified lignin-polyamine as asludge conditioner for the dewatering of secondary papermill sludge witha solid bowl centrifuge (Ingersoll-Rand). Table IV shows the benefit ofthe addition of the low cost lignin polyamine to PERCOL 763®. In orderto obtain adequate performance, 18-20 lbs PERCOL 763®/ODT (oven driedton) secondary sludge has to be used. Good mechanical floc strength isrequired in order to obtain clean centrate, which is low in suspendedparticulate matter.

                                      TABLE IV                                    __________________________________________________________________________    DEWATERING OF SECONDARY PAPERMILL SLUDGE                                      USING A SOLID BOWL CENTRIFUGE                                                                        Polymer                                                         Percent       +        Feed                                                   Lignin                                                                             Cake                                                                              Centrate                                                                           Lignin                                                                             Amine                                                                             Sludge                                                 Amine                                                                              Solids                                                                            Solids                                                                             Flow (%  Flow                                                                              Lbs/                                      Polymer  Content                                                                            %   (ppm).sup.(a)                                                                      (gpm)                                                                              Solids)                                                                           (gpm)                                                                             ODT                                       __________________________________________________________________________    13 lbs                                                                        PERCOL 763.sup.(b)                                                            plus:                                                                         130 lbs  50.0 9.5 830  8.0  (0.50)                                                                             300 22.22                                    10% lignin amine                                                              130 lbs  50.0 9.8 780  8.5  (0.50)                                                                             300 23.61                                    10% lignin amine                                                              160 lbs  55.2 8.9 860  8.0  (0.56)                                                                             300 24.90                                    10% lignin amine                                                              160 lbs  55.2 7.9 1,745                                                                              7.5  (0.56)                                                                             300 23.30                                    10% lignin amine                                                              200 lbs  60.6 8.9 1,890                                                                              7.5  (0.64)                                                                             300 26.70                                    10% lignin amine                                                              200 lbs  60.6 8.1 1,655                                                                              8.0  (0.64)                                                                             300 28.24                                    10% lignin amine                                                              __________________________________________________________________________     Note:                                                                         Conditions:                                                                   Feed solids: 1.2%                                                             Bowl speed: 1,440 rpm                                                         Scroll speed: 798 rpm                                                         .sup.(a) Less than 1,000 ppm, good; 1,000-2,000 ppm, acceptable               .sup.(b) Polyacrylamide manufactured by Allied Chemicals                 

EXAMPLE 18

This example shows the ability of lignin polyamines of Example 1 toprecipitate surface-active materials from dilute solution. Thesesurface-active materials, classified as wetting agents, detergents,emulsifiers, or dispersants, are environmentally non-acceptable and haveto be removed from waste water streams. Through the interaction of thephenolic groups, sulfonic acid groups and the carboxyl groups of thechemicals described below with the nitrogens of the lignin polyamines,water insoluble complexes are formed. These high molecular weightaggregates settle and can be removed from the water by filtration orcentrifugation techniques.

In a series of experiments 0.5 gram of surface active material wasdissolved in 800 ml of water and adjusted to pH 6.5-7.5. These dilutesolutions were titrated with 1.3% lignin polyamine solution (pH 2.5)until all the surface active material had been precpitated. The endpoint of the titration was reached when the dark color of the waterdisappeared or, in case of light colored water, until the water wasdarkened by the excess of lignin polyamine.

Table V shows the amount of lignin polyamine necessary to precipitatethe surface active chemicals.

                  TABLE V                                                         ______________________________________                                        PRECIPITATION OF SURFACE ACTIVE MATERIALS                                     WITH LIGNIN POLYAMINES                                                                               Solution (ml)                                                                 Added for                                              Surface Active Chemical                                                                              Precipitation                                          ______________________________________                                        Sulfonated kraft lignin A                                                                            17.4                                                   Sulfonated kraft lignin B                                                                            20.0                                                   Oxidized kraft lignin   8.9                                                   Kraft black liquor adjusted to pH 7                                                                   5.1                                                   Ammonium lignosulfonate (Orzan A ®)                                                              14.0                                                   Naphthalene sulfonate (Tamol SN ®)                                                               20.6                                                   Sulfonated tall oil fatty acid                                                                       18.0                                                   Carboxylated tall oil fatty acid                                                                     16.2                                                   (Diacid 1550 ®)                                                           Olefin sulfonate       15.8                                                   Dodecylbenzylsulfonate 17.2                                                   Tall oil N--methyl taurate                                                                           16.5                                                   ______________________________________                                    

After precipitation the floc size can be improved by addition of smallamounts (1-2 ml 0.5% solution) of high molecular weight cationicpolyacrylamides such as PERCOL 763® (manufactured by Allied Chemicals).

EXAMPLE 19

This example shows the efficiency of a quaternized lignin-polyamine as aretention aid for neutral size on pulp. The preferred lignin-polyamineis a derivative prepared with chlorohydroxypropyltrimethyl ammoniumchloride according to Example 7. Each sample contained 562 grams slurrypulp, 50 grams sodium bicarbonate for pH adjustment, 8.1 grams BKDemulsion (a commercially available ketene dimer alkaline size), and 0.3lb/ton Reten 523P (Hercules). In addition, samples #1-#3 contained 56.2grams (2 lbs/ton), 140.5 grams (5 lbs/ton), or 281 grams (10 lbs/ton)lignin-7N⁺ polyamine, a kraft lignin reacted withchlorohydroxypropyltrimethyl ammonium chloride. Samples #4-#6 likewisecontained 56.2 grams, 140.5 grams, and 281 grams of a Mannich-typelignin amine product, lignin polyamine-4N⁺ [softwood kraft ligninaminoethylpiperazine (3 moles)-formaldehyde (5 moles)-Quat 188 (4moles)]. Table VI shows the results obtained.

                  TABLE VI                                                        ______________________________________                                        EVALUATION OF QUATERNIZED LIGNIN                                              POLYAMINES AS RETENTION AID FOR                                               CATIONIC SIZE                                                                                     Size                                                                          Promoting                                                                             Reten Off-Machine                                       BKD,          Aid     523P, Sizing.sup.(a)                                                                         HST.sup.(b)                        Sample                                                                              #/ton   pH    #/ton   #/ton (sec.)   (sec.)                             ______________________________________                                        #1    2       8.0   2       0.3     11       686                              #2    2       8.0   5       0.3     38       928                              #3    2       8.0   10      0.3     37       861                              #4    2       8.0   2       0.3   1,247    1,178                              #5    2       8.0   5       0.3   1,598    1,152                              #6    2       8.0   10      0.3   3,020    1,734                              ______________________________________                                         .sup.(a) Hercules Size Test (HST)                                             .sup.(b) 7 days later                                                    

Excellent size retention was obtained by both products.

The results indicate that these products have potential as a cationicsize retention aid for kraft paper. Although the dark brown color oflignin tends to decrease the brightness of bleached paper, the quantityneeded for a specific amount of sizing may nevertheless meet brightnessqualifications for bleached paper.

EXAMPLE 20

This example shows the effectiveness of a lignin-formaldehyde-polyaminecondensate as a corrosion inhibitor for mild steel in mineral acids. Thetests were performed on 1010 mild steel coupons (Q-Panel Company,Cleveland, Ohio, about 6 sq. inches of surface area (3"×1"×1/8") and12.5 grams weight).

A condensation product of softwood kraft lignin, formaldehyde andaminoethylpiperazine as described in Example 1 was diluted to 13% solidsand acidified with hydrochloric acid as described in Example 10. Variousamounts of this solution were added to either 130 grams 2% hydrochloricacid or 130 grams 2% sulfuric acid prior to the insertion of the steelpanels. The corrosion test was carried out at 25° C., and theeffectiveness was determined by weight loss of the panels. The resultsare shown in Table VII.

                  TABLE VII                                                       ______________________________________                                        CORROSION INHIBITION OF MILD STEEL                                            IN HYDROCHLORIC AND SULFURIC ACID                                                      Inhibitor  Weight Loss (g)                                                    (mg)       50 hrs. 86 hrs.                                           ______________________________________                                        2% HCl     blank        0.3632  0.6731                                                   260          0.0664  0.1005                                                   520          0.0611  0.0850                                                   780          0.0555  0.0802                                                   1040         0.0538  0.0792                                                   1300         0.0526  0.0750                                        2% H.sub.2 SO.sub.4                                                                      blank        1.0234  1.4577                                                   260          0.0501  0.0755                                                   520          0.0440  0.0315                                                   780          0.0388  0.0616                                                   1040         0.0373  0.0599                                                   1300         0.0338  0.0576                                        ______________________________________                                    

While this invention has been described and illustrated herein byreferences to various specific materials, procedures and examples, it isunderstood that the invention is not restricted to the particularmaterials, combinations of materials, and procedures selected for thatpurpose. Numerous variations of such details can be employed, as will beappreciated by those skilled in the art.

What is claimed is:
 1. A method for inhibiting corrosion of mild steelin mineral acid comprising adding to the acid a lignin derivativeprepared by reacting lignin with an aldehyde, or an aldehyde producingsubstance, and a polyamine.
 2. The method of claim 1 wherein the ligninderivative starting lignin material is selected from the groupconsisting of lignin substantially free from sulfonic acid groups andlignin containing a significant amount of sulfonic acid groups.
 3. Themethod of claim 2 wherein the lignin substantially free from sulfonicacid groups is selected from the group consisting of kraft lignin, thelow molecular weight lignin by-product of vanillin production, anddesulfonated sulfite pulping process lignosulfonic acids.
 4. The methodof claim 2 wherein the lignin containing a significant amount ofsulfonic acid groups is selected from the group consisting oflignosulfonic acids.
 5. The method of claim 4 wherein the lignosulfonicacids are selected from the group consisting of lignosulfonic acidsisolated from spent sulfite pulping liquors and sulfonated kraft lignin.6. The method of claim 5 wherein the sulfonated kraft lignin is preparedby high temperature sulfonation.
 7. The method of claim 5 wherein thesulfonated kraft lignin is prepared by oxidative sulfonation at ambienttemperature.
 8. The method of claim 5 wherein the sulfonated kraftlignin is prepared by sulfomethylation.
 9. The method of claim 3 whereinthe lignin is kraft lignin selected from the group consisting ofhardwood lignin and softwood lignin.
 10. The method of claim 9 whereinthe kraft lignin is pretreated by demethylation.
 11. The method of claim1 wherein the lignin derivative is an ion selected from the groupconsisting of cation and anion.
 12. The method of claim 1 wherein thepolyamine is aminoethylpiperazine.
 13. The method of claim 12 whereinthe mineral acid is selected from the group consisting of hydrochloricacid and sulfuric acid.